Heat Pump Desuperheater and Charge Robber

ABSTRACT

Systems and methods are disclosed which may include providing a desuperheater/charge robber (DSHCR) system in a heating, ventilation, and/or air-conditioning (HVAC) system, wherein the DSHCR system is configured to selectively allow a flow of refrigerant through a desuperheater heat exchanger when the HVAC system is operated in a cooling mode and selectively prevent the flow of refrigerant through the desuperheater heat exchanger from a refrigerant fluid circuit when the HVAC system is operated in a heating mode. The desuperheater heat exchanger may also be configured to function as a charge robber and store at least a portion of the refrigerant when the HVAC system is operated in the heating mode.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. 119(e) to U.S.Provisional Patent Application No. 62/010,341 filed on Jun. 10, 2014 byStephen Stewart Hancock and entitled “Heat Pump Desuperheater and ChargeRobber,” the disclosure of which is hereby incorporated by reference inits entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

BACKGROUND

Heating, ventilation, and/or air conditioning (HVAC) systems maygenerally be used in residential and/or commercial structures to provideheating and/or cooling to climate-controlled areas within thesestructures. Some HVAC systems may be heat pump systems that include bothan indoor unit and an outdoor unit. In a heat pump system, refrigerantcharge management remains a critical part of the heat pump designbecause a majority of the heat pump system's refrigerant charge mayreside in the condenser, the condenser being the outdoor coil whenoperated in a cooling mode and the indoor coil when operated in aheating mode. In high efficiency heat pump systems, the outdoor coil isoften much larger than the indoor coil and capable of holding a largervolume of refrigerant. In such systems, a heat pump system charged withan adequate subcooling in the cooling mode may often experience anexcessive amount of subcooling in the heating mode, since much of theindoor coil may fill with liquid refrigerant. Traditional heat pumpsystems often utilize a cylinder, sometimes referred to as a “chargerobber,” that may fill with liquid refrigerant during operation of theheat pump system in the heating mode to sequester excess liquidrefrigerant which would otherwise flow to the indoor coil.

SUMMARY

In some embodiments of the disclosure, a heating, ventilation, and/orair-conditioning (HVAC) system is disclosed as comprising adesuperheater/charge robber (DSHCR) system configured to (1) selectivelyallow a flow of refrigerant through a desuperheater heat exchanger whenthe HVAC system is operated in a cooling mode and (2) selectivelyprevent the flow of refrigerant through the desuperheater heat exchangerfrom a refrigerant fluid circuit while keeping the desuperheater heatexchanger in fluid communication with a high pressure side of therefrigerant fluid circuit when the HVAC system is operated in a heatingmode.

In other embodiments of the disclosure, a method of operating an HVACsystem is disclosed as comprising: flowing refrigerant through adesuperheater heat exchanger when the HVAC system is operated in acooling mode; switching the HVAC system from the cooling mode to aheating mode; and preventing refrigerant from flowing through thedesuperheater heat exchanger while keeping the desuperheater heatexchanger in fluid communication with a high pressure side of therefrigerant fluid circuit when the HVAC system is operated in theheating mode.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and theadvantages thereof, reference is now made to the following briefdescription, taken in connection with the accompanying drawings anddetailed description:

FIG. 1 is a schematic diagram of an HVAC system comprising adesuperheater/charge robber system and configured in a cooling modeaccording to an embodiment of the disclosure;

FIG. 2 is a schematic diagram of the HVAC system of FIG. 1 comprisingthe desuperheater/charge robber system of FIG. 1 and configured in aheating mode according to an embodiment of the disclosure;

FIG. 3 is a schematic diagram of an HVAC system comprising adesuperheater/charge robber system and configured in a cooling modeaccording to another embodiment of the disclosure;

FIG. 4 is a schematic diagram of the HVAC system of FIG. 3 comprisingthe desuperheater/charge robber system of FIG. 3 and configured in aheating mode according to another embodiment of the disclosure;

FIG. 5 is a flowchart of a method of operating an HVAC system accordingto an embodiment of the disclosure; and

FIG. 6 is a flowchart of a method of operating an HVAC system accordingto another embodiment of the disclosure.

DETAILED DESCRIPTION

In some cases, it may be desirable to provide a desuperheater/chargerobber (DSHCR) system in a heating, ventilation, and/or air conditioning(HVAC) system. For example, in high efficiency heat pump systemscomprising both an indoor and an outdoor unit, where the outdoor coil ofthe outdoor unit is often much larger than the indoor coil of the indoorunit and capable of holding a larger volume of refrigerant, it may bedesirable to provide a DSHCR system to improve cooling performance whenthe heat pump system is operated in a cooling mode and to sequesterexcess liquid refrigerant during operation of the heat pump system in aheating mode. In some embodiments, systems and methods are disclosedthat comprise providing a DSHCR system in an outdoor unit of a heat pumpsystem that functions as a desuperheater in a cooling mode and a chargerobber in a heating mode.

Referring now to FIG. 1, a schematic diagram of an HVAC system 100comprising a DSHCR system 106 is shown configured in a cooling modeaccording to an embodiment of the disclosure. Most generally, HVACsystem 100 comprises a heat pump system that may be selectively operatedto implement one or more substantially closed thermodynamicrefrigeration cycles to provide a cooling functionality (hereinafter,“cooling mode”) and/or a heating functionality (hereinafter, “heatingmode”). Most generally, HVAC system 100, configured as a heat pumpsystem, generally comprises both an indoor unit 102 and an outdoor unit104. It will be appreciated that, although not pictured, the HVAC system100 may also comprise a system controller that is configured togenerally communicate with an indoor controller of the indoor unit 102and/or an outdoor controller of the outdoor unit 104 and/or controloperation of the indoor unit 102 and/or the outdoor unit 104.Additionally, the system controller may comprise a temperature sensorand may further be configured to control heating and/or cooling of zonesassociated with the HVAC system 100.

Indoor unit 102 generally comprises an indoor heat exchanger 108, anindoor fan 110, and an indoor metering device 112. Indoor heat exchanger108 may generally be configured to promote heat exchange betweenrefrigerant carried within internal tubing of the indoor heat exchanger108 and an airflow that may contact the indoor heat exchanger 108 butthat is segregated from the refrigerant. In some embodiments, indoorheat exchanger 108 may comprise a plate-fin heat exchanger. However, inother embodiments, indoor heat exchanger 108 may comprise a spine finheat exchanger, a microchannel heat exchanger, or any other suitabletype of heat exchanger.

The indoor fan 110 may generally comprise a centrifugal blowercomprising a blower housing, a blower impeller at least partiallydisposed within the blower housing, and a blower motor configured toselectively rotate the blower impeller. The indoor fan 110 may generallybe configured to provide airflow through the indoor unit 102 and/or theindoor heat exchanger 108 to promote heat transfer between the airflowand a refrigerant flowing through the indoor heat exchanger 108. Theindoor fan 110 may also be configured to deliver temperature-conditionedair from the indoor unit 102 to one or more areas and/or zones of aclimate controlled structure. The indoor fan 110 may generally comprisea mixed-flow fan and/or any other suitable type of fan. The indoor fan110 may generally be configured as a modulating and/or variable speedfan capable of being operated at many speeds over one or more ranges ofspeeds. In other embodiments, the indoor fan 110 may be configured as amultiple speed fan capable of being operated at a plurality of operatingspeeds by selectively electrically powering different ones of multipleelectromagnetic windings of a motor of the indoor fan 110. In yet otherembodiments, however, the indoor fan 110 may be a single speed fan.

The indoor metering device 112 may generally comprise anelectronically-controlled motor driven electronic expansion valve (EEV).In some embodiments, however, the indoor metering device 112 maycomprise a thermostatic expansion valve, a capillary tube assembly,and/or any other suitable metering device. In some embodiments, whilethe indoor metering device 112 may be configured to meter the volumeand/or flow rate of refrigerant through the indoor metering device 112,the indoor metering device 112 may also comprise and/or be associatedwith a refrigerant check valve and/or refrigerant bypass configurationwhen the direction of refrigerant flow through the indoor meteringdevice 112 is such that the indoor metering device 112 is not intendedto meter or otherwise substantially restrict flow of the refrigerantthrough the indoor metering device 112.

Outdoor unit 104 generally comprises an outdoor heat exchanger 114, acompressor 116, an outdoor fan 118, and an outdoor metering device 120.Additionally, as will be discussed later herein, the outdoor unit 104also comprises the DSHCR system 106. Further, it will be appreciatedthat while the reversing valve 122 may generally be associated with theoutdoor unit 104, the reversing valve 122 may be described as being acomponent of the DSHCR system 106, since operation of the DSHCR system106 relies heavily on the operation of the reversing valve 122. Outdoorheat exchanger 114 may generally be configured to promote heat transferbetween a refrigerant carried within internal passages of the outdoorheat exchanger 114 and an airflow that contacts the outdoor heatexchanger 114 but that is segregated from the refrigerant. In someembodiments, outdoor heat exchanger 114 may comprise a plate-fin heatexchanger. However, in other embodiments, outdoor heat exchanger 114 maycomprise a spine fin heat exchanger, a microchannel heat exchanger, orany other suitable type of heat exchanger.

The compressor 116 may generally comprise a multiple speed scroll-typecompressor that may generally be configured to selectively pumprefrigerant at a plurality of mass flow rates through the indoor unit102, the outdoor unit 104, and/or between the indoor unit 102 and theoutdoor unit 104. In some embodiments, however, the compressor 116 maycomprise a modulating compressor that is capable of operation over aplurality of speed ranges, a reciprocating-type compressor, a singlespeed compressor, and/or any other suitable refrigerant compressorand/or refrigerant pump.

The outdoor fan 118 may generally comprise an axial fan comprising a fanblade assembly and fan motor configured to selectively rotate the fanblade assembly. The outdoor fan 118 may generally be configured toprovide airflow through the outdoor unit 104 and/or the outdoor heatexchanger 114 to promote heat transfer between the airflow and arefrigerant flowing through the indoor heat exchanger 108. In someembodiments, and as will be discussed later herein, the outdoor fan 118may also be configured to provide airflow through a desuperheater heatexchanger 124. The outdoor fan 118 may generally be configured as amodulating and/or variable speed fan capable of being operated at aplurality of speeds over a plurality of speed ranges. In otherembodiments, the outdoor fan 118 may be configured as a multiple speedfan capable of being operated at a plurality of operating speeds byselectively electrically powering different multiple electromagneticwindings of a motor of the outdoor fan 118. In yet other embodiments,the outdoor fan 118 may be a single speed fan. Further, in otherembodiments, however, the outdoor fan 118 may comprise a mixed-flow fan,a centrifugal blower, and/or any other suitable type of fan and/orblower.

The outdoor metering device 120 may generally comprise a thermostaticexpansion valve. In some embodiments, however, the outdoor meteringdevice 120 may comprise an electronically-controlled motor driven EEVsimilar to indoor metering device 112, a capillary tube assembly, and/orany other suitable metering device. In some embodiments, while theoutdoor metering device 120 may be configured to meter the volume and/orflow rate of refrigerant through the outdoor metering device 120, theoutdoor metering device 120 may also comprise and/or be associated witha refrigerant check valve and/or refrigerant bypass configuration whenthe direction of refrigerant flow through the outdoor metering device120 is such that the outdoor metering device 120 is not intended tometer or otherwise substantially restrict flow of the refrigerantthrough the outdoor metering device 120.

DSHCR system 106 generally comprises a reversing valve 122, adesuperheater heat exchanger 124, and a three-way valve 126. Aspreviously stated, it will be appreciated that while the reversing valve122 may generally be associated with the outdoor unit 104, the reversingvalve 122 may be described herein as being a component of the DSHCRsystem 106, since operation of the DSHCR system 106 relies heavily onthe operation of the reversing valve 122. The reversing valve 122 maygenerally comprise a four-way reversing valve. The reversing valve 122comprises a main inlet port 136, a first variable port 130, a mainoutlet port 132, and a second variable port 134. As will be discussedlater herein, the reversing valve 122 may generally be selectivelycontrolled to alter a flowpath of refrigerant in the HVAC system 100 byselectively altering a refrigerant flowpath through the main inlet port136, the first variable port 130, the main outlet port 132, and thesecond variable port 134. In some embodiments, the reversing valve 122may be selectively controlled by an outdoor controller of the outdoorunit 104 and/or a system controller of the HVAC system 100. Thereversing valve 122 may also comprise an electrical solenoid, relay,and/or other device configured to selectively move a component of thereversing valve 122 between operational positions to alter the flowpathsthrough the reversing valve 122 and consequently the HVAC system 100.

The desuperheater heat exchanger 124, also commonly referred to assimply a desuperheater, may generally be described as comprising adesuperheater heat exchanger inlet 127 and a desuperheater heatexchanger outlet 129. The desuperheater heat exchanger inlet 127 maygenerally be connected in fluid communication with a first outlet port125 of a three-way valve 126, while the desuperheater heat exchangeroutlet 129 may generally be connected in fluid communication between asecond outlet port 128 of the three-way valve 126 and the main inletport 136 of the reversing valve 122. When the HVAC system 100 isoperated in the cooling mode, the desuperheater heat exchanger 124 maygenerally be configured to promote heat transfer between a refrigerantcarried within internal passages of the desuperheater heat exchanger 124and an airflow that contacts the desuperheater heat exchanger 124 butthat is segregated from the refrigerant. However, when the HVAC system100 is operated in the heating mode, the desuperheater heat exchanger124 may, in conjunction with other components of the DSHCR system 106,be removed from the refrigerant fluid circuit and perform the functionof a traditional charge robber to store excess liquid refrigerant. Insome embodiments, desuperheater heat exchanger 124 may comprise aplate-fin heat exchanger. However, in other embodiments, desuperheaterheat exchanger 124 may comprise a spine fin heat exchanger, amicrochannel heat exchanger, or any other suitable type of heatexchanger.

The three-way valve 126 may generally comprise a solenoid-actuatedvalve, a relay-controlled valve, and/or any other valve that isconfigured to selectively alter a flow of fluid through at least a firstand a second flowpath. The three-way valve 126 may generally comprise aninlet port 123, a first outlet port 125, and a second outlet port 128.The inlet port 123 of the three-way valve 126 may be connected in fluidcommunication with a discharge side of the compressor 116. The firstoutlet port 125 of the three-way valve 126 may generally be selectivelyconnected in fluid communication with the desuperheater heat exchangerinlet 127, while the second outlet port 128 may generally be selectivelyconnected in fluid communication with the main inlet port 136 of thereversing valve 122. The three-way valve 126 may generally be configuredto receive a flow of refrigerant from the compressor 116 that enters thethree-way valve 126 through the inlet port 123. Additionally, thethree-way valve 126 may be selectively controlled to divert refrigerantentering the inlet port 123 to the first outlet port 125 or the secondoutlet port 128, depending on the configuration of the three-way valve126 and/or the HVAC system 100. In some embodiments, the three-way valve126 may be selectively controlled by an outdoor controller of theoutdoor unit 104 and/or a system controller of the HVAC system 100.

Still referring to FIG. 1, the HVAC system 100 is shown configured foroperating in a cooling mode. When the HVAC system 100 is operated in thecooling mode, heat may generally be absorbed by refrigerant at theindoor heat exchanger 108 and rejected from the refrigerant at theoutdoor heat exchanger 114 and/or the desuperheater heat exchanger 124.Starting at the compressor 116, the compressor 116 may be operated tocompress refrigerant and pump the relatively high temperature and highpressure refrigerant to the inlet port 123 of the three-way valve 126,where the three-way valve 126 may be selectively configured to divertthe refrigerant to the first outlet port 125. Because the first outletport 125 is connected in fluid communication with the desuperheater heatexchanger inlet 127, refrigerant exiting the three-way valve 126 throughthe first outlet port 125 may enter the desuperheater heat exchanger 124through the desuperheater heat exchanger inlet 127.

Within the desuperheater heat exchanger 124, the relatively hightemperature refrigerant may transfer heat to an airflow passed throughand/or into contact with the desuperheater heat exchanger 124 by theoutdoor fan 118. After passing through the desuperheater heat exchanger124, refrigerant may exit the desuperheater heat exchanger 124 throughthe desuperheater heat exchanger outlet 129 and flow to a junction ofthe second outlet port 128 of the three-way valve 126 and the main inletport 136 of the reversing valve 122. Because the HVAC system 100 isconfigured for operation in the cooling mode, refrigerant may beprevented by the three-way valve 126 from entering the second outletport 128. Accordingly, refrigerant may enter the reversing valve 122through the main inlet port 136, where the reversing valve 122 may beselectively configured to divert the refrigerant to the second variableport 134.

Refrigerant may exit the reversing valve 122 through the second variableport 134 and flow to the outdoor heat exchanger 114, where therefrigerant may transfer additional heat to the airflow that is passedthrough and/or into contact with the outdoor heat exchanger 114 by theoutdoor fan 118, thereby condensing to a subcooled liquid-phaserefrigerant before exiting the outdoor heat exchanger 114 and flowing tothe outdoor metering device 120. By passing the heated refrigerantthrough the desuperheater heat exchanger 124 prior to passing therefrigerant through the outdoor heat exchanger 114 and by contacting theoutdoor heat exchanger 114 with an ambient airflow generated by theoutdoor fan 118 prior to the heated airflow encountering the relativelyhigher temperature desuperheater heat exchanger 124, the temperaturedifferentials between the airflow generated by the outdoor fan 118 andthe respective heat exchangers 124, 114 may be maximized. Accordingly,the desuperheater heat exchanger 124 and/or the DSHCR system 106 mayincrease cooling performance and/or the efficiency of the HVAC system100 as compared to a traditional system that may not comprise adesuperheater heat exchanger 124 and/or a DSHCR system 106.

After exiting the outdoor heat exchanger 114, the refrigerant may flowthrough and/or bypass the outdoor metering device 120, such thatrefrigerant flow is not substantially restricted by the outdoor meteringdevice 120. Refrigerant generally exits the outdoor metering device 120and flows to the indoor metering device 112, which may meter the flow ofrefrigerant through the indoor metering device 112, such that therefrigerant downstream of the indoor metering device 112 is at a lowerpressure than the refrigerant upstream of the indoor metering device112. The pressure differential across the indoor metering device 112allows the refrigerant downstream of the indoor metering device 112 toexpand and/or at least partially convert to a two-phase (vapor and gas)mixture. From the indoor metering device 112, the two-phase refrigerantmay enter the indoor heat exchanger 108. As the refrigerant is passedthrough the indoor heat exchanger 108, heat may be transferred to therefrigerant from an airflow that is passed through and/or into contactwith the indoor heat exchanger 108 by the indoor fan 110, therebycausing evaporation of the liquid-phase portion of the two-phaserefrigerant mixture. The refrigerant may exit the indoor heat exchanger108 and flow to the first variable port 130 of the reversing valve 122.In the cooling mode, the reversing valve 122 may be selectivelyconfigured to divert the refrigerant back to the compressor 116 throughthe main outlet port 132. At the compressor 116, the compressor 116 mayincrease the pressure of the refrigerant and the refrigeration cycle maybegin again.

Referring now to FIG. 2, a schematic diagram of the HVAC system 100 ofFIG. 1 comprising the DSHCR system 106 of FIG. 1 is shown configured ina heating mode according to an embodiment of the disclosure. When theHVAC system 100 is operated in the heating mode, heat may generally beabsorbed by refrigerant at the outdoor heat exchanger 114 and rejectedfrom the refrigerant at the indoor heat exchanger 108. Starting at thecompressor 116, the compressor 116 may similarly be operated to compressrefrigerant and pump the relatively high temperature and high pressurecompressed refrigerant to the inlet port 123 of the three-way valve 126.However, in a heating mode configuration, the three-way valve 126 may beselectively configured to divert the refrigerant entering the inlet port123 to the second outlet port 128 as opposed to the first outlet port125. Refrigerant exiting the second outlet port 128 may encounter thejunction of the desuperheater heat exchanger outlet 129 and the maininlet port 136 of the reversing valve 122. Because the HVAC system 100may be configured for operation in the heating mode, refrigerant may notenter through the first outlet port 125 of the three-way valve 126, andthus not enter the desuperheater heat exchanger 124 through thedesuperheater heat exchanger outlet 129. Accordingly, the desuperheaterheat exchanger 124 is effectively removed from the refrigerant fluidcircuit.

As a result of removing the desuperheater heat exchanger 124 from therefrigerant fluid circuit when the HVAC system 100 is operated in aheating mode, the desuperheater heat exchanger 124 remains functionallyidle with respect to refrigerant flow. However, the desuperheater heatexchanger 124 may be configured to sequester excess liquid refrigerantthat is not needed for a heating operation in HVAC system 100.Therefore, the desuperheater heat exchanger 124 may perform the functionof a traditional charge robber in the heating mode by sequesteringexcess liquid refrigerant that traditionally may backup in the indoorheat exchanger 108 and reduce the efficiency of the HVAC system 100.Additionally, as a result of the location of the desuperheater heatexchanger 124 in the refrigeration circuit, the desuperheater heatexchanger 124 and/or DSHCR system 106 may sequester excess liquidrefrigerant at a location that is as far upstream from the compressor116 as possible. Accordingly, the desuperheater heat exchanger 124and/or the DSHCR system 106 may prevent excess liquid refrigerant thatposes a potential damage risk to the compressor 116 from entering thecompressor 116, thereby increasing the reliability of the compressor 116and/or preventing damage to the compressor 116.

Additionally, by locating the desuperheater heat exchanger 124 on thehigh pressure side of the reversing valve 122, air passing over thedesuperheater heat exchanger 124 may be below saturation temperature,which may condense refrigerant in the desuperheater heat exchanger 124into liquid refrigerant. As such, by removing the desuperheater heatexchanger 124 from the refrigerant fluid circuit, liquid refrigerantthat may condense in the desuperheater heat exchanger 124 may further besequestered from the indoor heat exchanger 108 and/or the compressor116. Further, in addition to increasing the cooling performance and/orefficiency of the HVAC system 100 when the HVAC system 100 is operatedin the cooling mode, the desuperheater heat exchanger 124 and/or theDSHCR system 106 may improve heating performance by performing thefunction of a traditional charge robber by sequestering the excessliquid refrigerant without the additional cost and complexity of addinga traditional charge robbing system.

Refrigerant exiting the three-way valve 126 through the second outletport 128 may thus enter the reversing valve 122 through the main inletport 136. In a heating mode configuration, the reversing valve 122 maybe selectively configured to divert the refrigerant entering the maininlet port 136 to the first variable port 130 as opposed to the secondvariable port 134 during operation of the HVAC system 100 in a coolingmode. Refrigerant may exit the reversing valve 122 through the firstvariable port 130 and flow to the indoor heat exchanger 108. Bydiverting the incoming flow to the first variable port 130 and to theindoor heat exchanger 108 prior to the outdoor heat exchanger 114, itwill be appreciated that refrigerant flow through the HVAC system 100 iseffectively reversed.

The high temperature refrigerant may then flow to the indoor heatexchanger 108 where it may transfer heat to an airflow that is passedthrough and/or into contact with the indoor heat exchanger 108. Afterexiting the indoor heat exchanger 108, the refrigerant may flow throughand/or bypass the indoor metering device 112, such that refrigerant flowis not substantially restricted by the indoor metering device 112.Refrigerant generally exits the indoor metering device 112 and flows tothe outdoor metering device 120, which may meter the flow of refrigerantthrough the outdoor metering device 120, such that the refrigerantdownstream of the outdoor metering device 120 is at a lower pressurethan the refrigerant upstream of the outdoor metering device 120. Fromthe outdoor metering device 120, the refrigerant may enter the outdoorheat exchanger 114. As the refrigerant is passed through the outdoorheat exchanger 114, heat may be transferred to the refrigerant from anairflow that is passed through and/or into contact with the outdoor heatexchanger 114 by the outdoor fan 118. Refrigerant leaving the outdoorheat exchanger 114 may enter the second variable port 134 of thereversing valve 122, where the reversing valve 122 may be selectivelyconfigured to divert the refrigerant to the main outlet port 132 andconsequently back to the compressor 116, where the refrigeration cyclemay begin again.

Referring now to FIG. 3, a schematic diagram of an HVAC system 200comprising a DSHCR system 206 is shown configured in a cooling modeaccording to another embodiment of the disclosure. Most generally, HVACsystem 200 may comprise a heat pump system and be substantially similarto HVAC system 100 of FIGS. 1-2 in that HVAC system 200 generallycomprises an indoor unit 202 and an outdoor unit 204. Accordingly,indoor unit 202 may be substantially similar to indoor unit 102 andgenerally comprises an indoor heat exchanger 208, an indoor fan 210, andan indoor metering device 212. Further, outdoor unit 204 may besubstantially similar to outdoor unit 104 and generally comprises anoutdoor heat exchanger 214, a compressor 216, an outdoor fan 218, and anoutdoor metering device 220. However, outdoor unit 204 comprises analternatively-configured DSHCR system 206. Further, it will beappreciated that while the reversing valve 222 may generally beassociated with the outdoor unit 204, the reversing valve 222 may bedescribed as being a component of the DSHCR system 206, since operationof the DSHCR system 206 relies heavily on the operation of the reversingvalve 222. It will also be appreciated that, although not pictured, theHVAC system 200 may also comprise a system controller that is configuredto generally communicate with an indoor controller of the indoor unit202 and/or an outdoor controller of the outdoor unit 204 and/or controloperation of the indoor unit 202 and/or the outdoor unit 204.Additionally, the system controller may comprise a temperature sensorand may further be configured to control heating and/or cooling of zonesassociated with the HVAC system 200.

DSHCR system 206 may be substantially similar to DSHCR system 106 andgenerally comprises a reversing valve 222 and a desuperheater heatexchanger 224. As opposed to the four-way reversing valve 122 used inDSHCR 106, reversing valve 222 may generally comprise a five-wayreversing valve that may be substantially similar to the five-wayreversing valve disclosed in U.S. patent application Ser. No.14/720,170, filed on May 22, 2015 by Hancock and entitled “Five-Way HeatPump Reversing Valve,” the disclosure of which is hereby incorporated byreference in its entirety. In some embodiments, the five-way reversingvalve 222 may provide additional functionality that may eliminate theneed for additional components, i.e. three-way valve 126 used in DSHCR106 in FIGS. 1-2. The five-way reversing valve 222 comprises a firstinlet port 236, a second inlet port 238, a first variable port 230, amain outlet port 232, and a second variable port 234. As will bediscussed later herein, the reversing valve 222 may generally beselectively controlled to alter a flowpath of refrigerant in the HVACsystem 200 by selectively altering a refrigerant flowpath through thefirst inlet port 236, the second inlet port 238, the first variable port230, the main outlet port 232, and the second variable port 234. Thereversing valve 222 may also comprise an electrical solenoid, relay,and/or other device configured to selectively move a component of thereversing valve 222 between operational positions to alter the flowpathsthrough the reversing valve 222 and consequently the HVAC system 200.Additionally, the reversing valve 222 may be selectively controlled by asystem controller and/or an outdoor controller.

The desuperheater heat exchanger 224 may generally be described ascomprising a desuperheater inlet 227 and a desuperheater outlet 229. Thedesuperheater inlet 227 may generally be selectively connected in fluidcommunication with a discharge side of the compressor 216 and the firstinlet port 236 of the reversing valve 222, while the desuperheateroutlet 229 may be connected in fluid communication with the second inletport 238 of the reversing valve 222. When the HVAC system 200 isoperated in the cooling mode, the desuperheater heat exchanger 224 maygenerally be configured to promote heat transfer between a refrigerantcarried within internal passages of the desuperheater heat exchanger 224and an airflow that contacts the desuperheater heat exchanger 224 butthat is segregated from the refrigerant. However, when the HVAC system200 is operated in the heating mode, the desuperheater heat exchanger224 may perform the function of a traditional charge robber to storeexcess liquid refrigerant. In some embodiments, desuperheater heatexchanger 224 may comprise a plate-fin heat exchanger. However, in otherembodiments, desuperheater heat exchanger 224 may comprise a spine finheat exchanger, a microchannel heat exchanger, or any other suitabletype of heat exchanger.

Still referring to FIG. 3, the HVAC system 200 is shown configured foroperating in a cooling mode. When the HVAC system 200 is operated in thecooling mode, heat may generally be absorbed by refrigerant at theindoor heat exchanger 208 and rejected from the refrigerant at theoutdoor heat exchanger 214 and/or the desuperheater heat exchanger 224.Starting at the compressor 216, the compressor 216 may be operated tocompress refrigerant and pump the relatively high temperature and highpressure refrigerant to the desuperheater inlet 227. In this embodiment,and when the HVAC system 200 is operated in the cooling mode, thereversing valve 222 may be configured such that refrigerant flow fromthe compressor 216 does not enter the first inlet port 236 of thereversing valve 222 and flow through the reversing valve 222. Thecompressor 216 instead delivers refrigerant to the desuperheater heatexchanger 224 through the desuperheater heat exchanger inlet 227, wherethe refrigerant may flow through the desuperheater heat exchanger 224.

Within the desuperheater heat exchanger 224, the relatively hightemperature refrigerant may transfer heat to an airflow passed throughand/or into contact with the desuperheater heat exchanger 224 by theoutdoor fan 218. After passing through the desuperheater heat exchanger224, refrigerant may exit the desuperheater heat exchanger 224 throughthe desuperheater outlet 229 and flow to the second inlet port 238 ofthe reversing valve 222. The reversing valve 222 may be configured toallow refrigerant to enter the reversing valve 222 through the secondinlet port 238, flow through the reversing valve 222, and exit thereversing valve 222 through the second variable port 234. In someembodiments, when the HVAC system 200 is configured in the cooling modeof operation, the flowpath through the reversing valve 222 from thesecond inlet port 238 to the second variable port 234 may comprise asubstantially straight, linear flowpath, which may, in some embodiments,reduce a pressure drop through the reversing valve 222 and/or provide anincrease in efficiency of the HVAC system 200 over a reversing valve 222having a substantially non-linear flowpath.

Refrigerant exiting the reversing valve 222 through the second variableport 234 may flow to the outdoor heat exchanger 214, where therefrigerant may transfer additional heat to the airflow that is passedthrough and/or into contact with the outdoor heat exchanger 214 by theoutdoor fan 218, thereby condensing to a subcooled liquid-phaserefrigerant before exiting the outdoor heat exchanger 214 and flowing tothe outdoor metering device 220. By passing the heated refrigerantthrough the desuperheater heat exchanger 224 prior to passing therefrigerant through the outdoor heat exchanger 214 and by contacting theoutdoor heat exchanger 214 with an ambient airflow generated by theoutdoor fan 218 prior to the heated airflow encountering the relativelyhigher temperature desuperheater heat exchanger 224, the temperaturedifferentials between the airflow generated by the outdoor fan 218 andthe respective heat exchangers 224, 214 may be maximized. Accordingly,the desuperheater heat exchanger 224 and/or the DSHCR system 206 mayincrease the cooling performance and/or the efficiency of the HVACsystem 200 as compared to a traditional system that may not comprise adesuperheater heat exchanger 224 and/or a DSHCR system 206.

After exiting the outdoor heat exchanger 214, the refrigerant may flowthrough and/or bypass the outdoor metering device 220, such thatrefrigerant flow is not substantially restricted by the outdoor meteringdevice 220. Refrigerant generally exits the outdoor metering device 220and flows to the indoor metering device 212, which may meter the flow ofrefrigerant through the indoor metering device 212, such that therefrigerant downstream of the indoor metering device 212 is at a lowerpressure than the refrigerant upstream of the indoor metering device212. The pressure differential across the indoor metering device 212allows the refrigerant downstream of the indoor metering device 212 toexpand and/or at least partially convert to a two-phase (vapor and gas)mixture. From the indoor metering device 212, the two-phase refrigerantmay enter the indoor heat exchanger 208. As the refrigerant is passedthrough the indoor heat exchanger 208, heat may be transferred to therefrigerant from an airflow that is passed through and/or into contactwith the indoor heat exchanger 208 by the indoor fan 210, therebycausing evaporation of the liquid-phase portion of the two-phaserefrigerant mixture. The refrigerant may exit the indoor heat exchanger208 and flow to the first variable port 230 of the reversing valve 222.In the cooling mode, the reversing valve 222 may be selectivelyconfigured to divert the refrigerant back to the compressor 216 throughthe main outlet port 232. At the compressor 216, the compressor 216 mayagain increase the pressure of the refrigerant and the refrigerationcycle may begin again.

Referring now to FIG. 4, a schematic diagram of the HVAC system 200 ofFIG. 3 comprising the DSHCR system 206 of FIG. 3 is shown configured ina heating mode according to another embodiment of the disclosure. Whenthe HVAC system 200 is operated in the heating mode, heat may generallybe absorbed by refrigerant at the outdoor heat exchanger 214 andrejected from the refrigerant at the indoor heat exchanger 208. Startingat the compressor 216, the compressor 216 may similarly be operated tocompress refrigerant and pump the relatively high temperature and highpressure compressed refrigerant to the first inlet port 236 of thereversing valve 222. While the discharge of the compressor 216 remainsin fluid communication with the desuperheater heat exchanger 224, thereversing valve 222 may be selectively configured to prevent refrigerantfrom passing through the reversing valve 222 via the second inlet port238. As a result, substantially no refrigerant passes through thedesuperheater heat exchanger 224 during operation of the HVAC system 200in the heating mode. Thus, when the HVAC system 200 is operated in theheating mode, the desuperheater heat exchanger 224 remains functionallyidle with respect to refrigerant flow. However, the desuperheater heatexchanger 224 may be configured to sequester excess refrigerant that isnot needed for a heating operation in HVAC system 200. Therefore, thedesuperheater heat exchanger 224 may perform the function of atraditional charge robber in the heating mode by sequestering excessliquid refrigerant that traditionally may backup in the indoor heatexchanger 208 and reduce the efficiency of the HVAC system 200.

Additionally, as a result of the location of the desuperheater heatexchanger 224 in the refrigeration circuit, the desuperheater heatexchanger 224 and/or DSHCR system 206 may sequester excess liquidrefrigerant at a location that is as far upstream from the compressor216 as possible. Accordingly, the desuperheater heat exchanger 224and/or the DSHCR system 206 may prevent excess liquid refrigerant thatposes a potential damage risk to the compressor 216 from entering thecompressor 216, thereby increasing the reliability of the compressor 216and/or preventing damage to the compressor 216. Further, in addition toincreasing the cooling performance and/or efficiency of the HVAC system200 when the HVAC system 200 is operated in the cooling mode, thedesuperheater heat exchanger 224 and/or the DSHCR system 206 may improveheating performance by performing the function of a traditional chargerobber by sequestering the excess liquid refrigerant without theadditional cost and complexity of adding a traditional charge robbingsystem.

Continuing through the heating cycle, refrigerant entering the firstinlet port 236 of the reversing valve 222 may flow through the reversingvalve 222 and exit the reversing valve 222 via the first variable port230. The high temperature refrigerant may then flow to the indoor heatexchanger 208 where it may transfer heat to an airflow that is passedthrough and/or into contact with the indoor heat exchanger 208 by theindoor fan 210. After exiting the indoor heat exchanger 208, therefrigerant may flow through and/or bypass the indoor metering device212, such that refrigerant flow is not substantially restricted by theindoor metering device 212. Refrigerant generally exits the indoormetering device 212 and flows to the outdoor metering device 220, whichmay meter the flow of refrigerant through the outdoor metering device220, such that the refrigerant downstream of the outdoor metering device220 is at a lower pressure than the refrigerant upstream of the outdoormetering device 220. From the outdoor metering device 220, therefrigerant may enter the outdoor heat exchanger 214. As the refrigerantis passed through the outdoor heat exchanger 214, heat may betransferred to the refrigerant from an airflow that is passed throughand/or into contact with the outdoor heat exchanger 214 by the outdoorfan 218. Refrigerant leaving the outdoor heat exchanger 214 may flow tothe second variable port 234 of the reversing valve 222, where thereversing valve 222 may be selectively configured to divert therefrigerant to exit the reversing valve 222 through the main outlet port232 and consequently back to the compressor 216, where the refrigerationcycle may begin again.

Referring now to FIG. 5, a flowchart of a method 300 of operating anHVAC system is shown according to an embodiment of the disclosure. Themethod 300 may begin at block 302 by flowing refrigerant through adesuperheater heat exchanger. In some embodiments, flowing refrigerantthrough the desuperheater heat exchanger may be accomplished byoperating the HVAC system in a cooling mode. In some embodiments, thedesuperheater heat exchanger may comprise desuperheater heat exchanger124 of FIGS. 1-2. In other embodiments, the desuperheater heat exchangermay comprise desuperheater heat exchanger 224 of FIGS. 3-4. The method300 may continue at block 304 by switching the HVAC system from thecooling mode to a heating mode. The method 300 may conclude at block 306by preventing refrigerant from flowing through the desuperheater heatexchanger when the HVAC system is operated in the heating mode. In someembodiments, this may be accomplished by configuring components of aDSHCR 106, 206 to remove the desuperheater heat exchanger from therefrigerant fluid circuit.

Referring now to FIG. 6, a flowchart of a method 400 of operating anHVAC system is shown according to another embodiment of the disclosure.The method may begin at block 402 by selecting a mode of operation ofthe HVAC system. If a cooling mode of operation is selected, the method400 may continue at block 404. At block 404, a five-way reversing valvemay be selectively configured to allow the flow of refrigerant through adesuperheater heat exchanger. However, if a heating mode of operation isselected at block 402, the method 400 may continue to block 406. Atblock 406, the five-way reversing valve may be selectively configured torestrict and/or prevent the flow of refrigerant through thedesuperheater heat exchanger. In some embodiments, at block 406, whenrefrigerant flow through the desuperheater heat exchanger is restricted,the desuperheater heat exchanger may still remain in fluid communicationwith a high pressure side of the refrigerant fluid circuit. Morespecifically, in some embodiments, the desuperheater heat exchanger maystill remain in fluid communication with a discharge side of acompressor of the HVAC system.

At least one embodiment is disclosed and variations, combinations,and/or modifications of the embodiment(s) and/or features of theembodiment(s) made by a person having ordinary skill in the art arewithin the scope of the disclosure. Alternative embodiments that resultfrom combining, integrating, and/or omitting features of theembodiment(s) are also within the scope of the disclosure. Wherenumerical ranges or limitations are expressly stated, such expressranges or limitations should be understood to include iterative rangesor limitations of like magnitude falling within the expressly statedranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4,etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example,whenever a numerical range with a lower limit, R_(l), and an upperlimit, R_(u), is disclosed, any number falling within the range isspecifically disclosed. In particular, the following numbers within therange are specifically disclosed: R=R₁−k*(R_(u)−R_(l)), wherein k is avariable ranging from 1 percent to 100 percent with a 1 percentincrement, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5percent, . . . , 50 percent, 51 percent, 52 percent, . . . , 95 percent,96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Unlessotherwise stated, the term “about” shall mean plus or minus 10 percentof the subsequent value. Moreover, any numerical range defined by two Rnumbers as defined in the above is also specifically disclosed. Use ofthe term “optionally” with respect to any element of a claim means thatthe element is required, or alternatively, the element is not required,both alternatives being within the scope of the claim. Use of broaderterms such as comprises, includes, and having should be understood toprovide support for narrower terms such as consisting of, consistingessentially of, and comprised substantially of. Accordingly, the scopeof protection is not limited by the description set out above but isdefined by the claims that follow, that scope including all equivalentsof the subject matter of the claims. Each and every claim isincorporated as further disclosure into the specification and the claimsare embodiment(s) of the present invention.

What is claimed is:
 1. A heating, ventilation, and/or air-conditioning(HVAC) system, comprising: a desuperheater/charge robber (DSHCR) systemconfigured to (1) selectively allow a flow of refrigerant through adesuperheater heat exchanger when the HVAC system is operated in acooling mode and (2) selectively prevent the flow of refrigerant throughthe desuperheater heat exchanger from a refrigerant fluid circuit whilekeeping the desuperheater heat exchanger in fluid communication with ahigh pressure side of the refrigerant fluid circuit when the HVAC systemis operated in a heating mode.
 2. The HVAC system of claim 1, furthercomprising: a three-way valve.
 3. The HVAC system of claim 2, whereinthe three-way valve is configured to divert refrigerant to thedesuperheater heat exchanger when the HVAC system is operated in thecooling mode.
 4. The HVAC system of claim 2, wherein the three-way valveis configured to divert refrigerant to flow to the reversing valve whenthe HVAC system is operated in the heating mode.
 5. The HVAC system ofclaim 2, wherein the three-way valve is configured to preventrefrigerant from flowing through the desuperheater heat exchanger whenthe HVAC system is configured in the heating mode.
 6. The HVAC system ofclaim 1, wherein the desuperheater heat exchanger is configured topromote heat exchange between the refrigerant and an airflow generatedby an outdoor fan of the HVAC system when the HVAC system is operated inthe cooling mode.
 7. The HVAC system of claim 1, wherein thedesuperheater heat exchanger is configured to sequester at least aportion of the refrigerant when the HVAC system is operated in theheating mode.
 8. The HVAC system of claim 1, further comprising: afour-way reversing valve.
 9. The HVAC system of claim 8, wherein thedesuperheater heat exchanger is configured to deliver refrigerant to thereversing valve of the HVAC system when the HVAC system is operated inthe cooling mode.
 10. The HVAC system of claim 8, wherein the four-wayreversing valve is configured to reverse the flow of refrigerant throughat least one of an indoor heat exchanger of the HVAC system and anoutdoor heat exchanger of the HVAC system.
 11. The HVAC system of claim1, further comprising: a five-way reversing valve.
 12. The HVAC systemof claim 11, wherein the five-way reversing valve is configured toreverse the flow of refrigerant through at least one of an indoor heatexchanger of the HVAC system and an outdoor heat exchanger of the HVACsystem.
 13. The HVAC system of claim 11, wherein the five-way reversingvalve is configured to allow refrigerant to flow through thedesuperheater heat exchanger when the HVAC system is configured in acooling mode.
 14. The HVAC system of claim 11, wherein the five-wayreversing valve is configured to prevent refrigerant from flowingthrough the desuperheater heat exchanger when the HVAC system isconfigured in a heating mode.
 15. The HVAC system of claim 1, whereinthe HVAC system is configured as a heat pump HVAC system.
 16. A methodof operating a heating, ventilation, and/or air-conditioning (HVAC)system, comprising: flowing refrigerant through a desuperheater heatexchanger when the HVAC system is operated in a cooling mode; switchingthe HVAC system from the cooling mode to a heating mode; and preventingrefrigerant from flowing through the desuperheater heat exchanger whilekeeping the desuperheater heat exchanger in fluid communication with ahigh pressure side of a refrigerant fluid circuit when the HVAC systemis operated in the heating mode.
 17. The method of claim 16, furthercomprising: storing at least a portion of the refrigerant in thedesuperheater heat exchanger when the HVAC system is operated in theheating mode.
 18. The method of claim 16, wherein the switching the HVACsystem from the cooling mode to a heating mode is accomplished byselectively configuring at least one of a three-way reversing valve, afour-way reversing valve, and a five-way reversing valve.
 19. The methodof claim 16, wherein the preventing refrigerant from flowing through thedesuperheater heat exchanger is accomplished by selectively configuringa three-way reversing valve and a four-way reversing valve to remove thedesuperheater heat exchanger from a refrigerant fluid circuit.
 20. Themethod of claim 16, wherein the preventing refrigerant from flowingthrough the desuperheater heat exchanger is accomplished by selectivelyconfiguring a five-way reversing valve to remove the desuperheater heatexchanger from a refrigerant fluid circuit.